package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IUserService userService;

    /**
     * 关注或者取关功能
     * @param followUserId
     * @param isFollow
     * @return
     */
    @Override
    public Result follow(Long followUserId, Boolean isFollow) {

        //获取用户id
        Long userId = UserHolder.getUser().getId();
        String key = "follow:" + userId;
        //1. 判断关注还是取关
        if (isFollow){
            //2. 关注，新增数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSuccess = save(follow);
            if (isFollow){
                //把关注目标用户id放入redis集合 sadd userId followUserId
                stringRedisTemplate.opsForSet().add(key, followUserId.toString());
            }
        }else {
            //3. 取关 delete from tb_follow where userId = ? and follow_user_id = ?
            boolean idSuccess = remove(new QueryWrapper<Follow>()
                    .eq("user_id", userId)
                    .eq("follow_user_id", followUserId));
            if (idSuccess){
                //关注的用户id从redis中移除
                stringRedisTemplate.opsForSet().remove(key,followUserId.toString());
            }
        }
        return Result.ok();
    }

    /**
     * 判断用户是否关注
     * @param followUserId
     * @return
     */
    @Override
    public Result idFollow(Long followUserId) {
        //1. 获取用户id
        Long userId = UserHolder.getUser().getId();
        //2. 查询是否关注
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
        //3. 判断
        return Result.ok(count > 0);
    }

    /**
     * 共同关注
     * @param bloggerId
     * @return
     */
    @Override
    public Result mutualFollowedAccount(Long bloggerId) {
        //1. 获取本身登陆用户id
        Long userId = UserHolder.getUser().getId();
        String key = "follow:" + userId;
        //2. 目标用户的key
        String key2 = "follow:" + bloggerId;
        //求交集
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key2);
        //有可能没有交集
        if (intersect == null){
            //无交集
            return Result.ok(Collections.emptyList());
        }
        //3. 解析id集合
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        //4. 查询用户
        List<UserDTO> users = userService.listByIds(ids)
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(users);
    }
}
